package com.dy.串;

public interface IString {
    public void clear();

    public boolean isEmpty();

    public int length();

    public char charAt(int index);

    public IString substring(int begin, int end);

    public IString insert(int offset, IString str);

    public IString delete(int begin, int end);

    public IString concat(IString str);

    public int compareTo(IString str);

    public int indexOf(IString str, int begin);
}
